Intent of removePoller_removes_entry, removePoller_does_not_affect_other_entries

All 2 exact tests in this concept. Every test is marked by where it enters the hierarchy.

go.temporal.io/ 2 tests
- server/ 2 tests
  - service/ 2 tests
    
    matching/ 2 tests
    
    TestPollerHistory/ 2 tests
    
    go.temporal.io/server/service/matching/TestPollerHistory/removePoller_does_not_affect_other_entries Introduced here
    
    go.temporal.io/server/service/matching/TestPollerHistory/removePoller_removes_entry Introduced here